Copper diffusion in cable-insulating materials by chemiluminescence and DSC techniques

Abstract

Chemiluminescence (CL) and differential scanning calorimetry (DSC) were applied for proving the copper ion migration processes occurring within the lowdensity polyethylene (LDPE) electrical insulator as a consequence of intimate contact. Thin LDPE slides of 0.5 mm thick were subjected to short-time thermal stress at temperatures between 80 and 120°C. Both CL and DSC kinetic parameters revealed the acceleration of posttreatment oxidation at elevated temperatures (170-200°C) in copper-contacting polymer as in respect to the cases when Cu was absent. It was revealed that the oxidation rate measured by CL was more than two times higher for the samples heated in the presence of Cu than in its absence, while the oxidation induction time from DSC was considerably lowered for the same samples. Elemental analysis data provided by atomic absorption spectroscopy and particle-induced X-ray emission techniques as well as SEM investigations confirmed the presence of copper within the samples subjected to thermal treatment when the polymer insulation was in contact with the metallic conductor. Chemiluminescence procedure has a remarkable sensitivity to detect the effect of copper in the polymer matrix even at low concentrations.

Characterization Techniques of Polymer Aging: From Beginning to End

“…398 In addition, the inorganic fillers with transitional metal or carboxylic acids may show superiorities in catalyzing the decomposition of hydroperoxide and affecting the oxidative aging, manifested as changes in the shape and intensity of CL emission. 405,410,414 The high sensitivity and capacity for online monitoring made the CL available in the thermal stability evaluation for newly designed polymers such as propylene grafted with acrylic acid 343 and polyurethanes modified by octa(3-hydroxy-3-methylbutylmethylsiloxy) POSS (o-POSS). 417 Moreover, the reinforced properties for polymer blends could also be investigated by CL measurements such as the poly(lactic acid) (PLA)/styreneisoprene-styrene triblock polymer blends, 418 and PA-6/ethylene elastomer blends.…”

“…They have further studied the stabilization effects of Ce-doped PbZrTiO 3 through trapping and blocking the radicals, and the defect in the surface of the fillers could strengthen this effect . In addition, the inorganic fillers with transitional metal or carboxylic acids may show superiorities in catalyzing the decomposition of hydroperoxide and affecting the oxidative aging, manifested as changes in the shape and intensity of CL emission. ,, …”